Oracle Database MCQ

Test your knowledge with important Oracle Database MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Oracle Database MCQs at Bissoy

• An n-array relationship is drawn using which symbol:
  ক

  A diamond

  খ

  A line with arrows showing direction

  গ

  A line without arrows showing direction

  ঘ

  A rectangle
• An aggregation association is drawn using which symbol:
  ক

  a line which loops back onto the same table

  খ

  small closed diamond at the end of a line connecting two tables

  গ

  small open diamond at the end of a line connecting two tables

  ঘ

  small triangle at the end of a line connecting the aggregated item and multiple component items
• The relational model is based on the concept that data is organized and stored in two-dimensional tables called _____________
  ক

  Fields

  খ

  Records

  গ

  Relations

  ঘ

  Keys
• Identify the criteria for designing database from the point of view of user
  ক

  No redundancy

  খ

  No inapplicable attributes

  গ

  Uniformity in naming & definitions of the data items

  ঘ

  All of the Mentioned
• A ___________ normal form normalization will be needed where all attributes in a relation tuple are not functionally dependent only on the key attribute.
  ক

  First

  খ

  Second

  গ

  Third

  ঘ

  Fourth
• E-R model uses this symbol to represent weak entity set ?
  ক

  Dotted rectangle

  খ

  Diamond

  গ

  Doubly outlined rectangle

  ঘ

  None of the Mentioned
• The relational model feature is that there
  ক

  is no need for primary key data

  খ

  is much more data independence than some other database models

  গ

  are explicit relationships among records

  ঘ

  are tables with many dimensions
• A relational database developer refers to a record as
  ক

  A criteria

  খ

  A relation

  গ

  A tuple

  ঘ

  An attribute
• In an E-R diagram an entity set is represent by a
  ক

  Rectangle

  খ

  Ellipse

  গ

  Diamond box

  ঘ

  Circle
• In a database, a foreign key is ?
  ক

  A data element/attribute within a data field of a data record that is not unique, and cannot be used to distinguish one data record in a database from another data record within a database table

  খ

  A data element/attribute within a data field of a data record within a database table that is a secondary key in another database table

  গ

  A data element/attribute within a data field of a data record within a database table that is a primary key in another database table

  ঘ

  A data element/attribute within a data field of a data record that enables a database to uniquely distinguish one data record in a database from another data record within a database table
• A Foreign key is combined with a foreign key creates
  ক

  Parent child relationship between the tables that connect them

  খ

  Many-Many relationship between the tables that connect them

  গ

  Network model between the tables that connect them

  ঘ

  None of the Mentioned
• Which key accepts multiple NULL values?
  ক

  Foreign Key

  খ

  Unique Key

  গ

  Primary Key

  ঘ

  None of the Mentioned
• A Key which is a set of one or more columns that can identify a record uniquely is called?
  ক

  Natural key

  খ

  Candidate key

  গ

  Not Null key

  ঘ

  Alternate key
• By default, which key creates Clustered index?
  ক

  Foreign Key

  খ

  Unique Key

  গ

  Primary Key

  ঘ

  None of the Mentioned
• What is true about Unique and primary key?
  ক

  Unique can have multiple NULL values but Primary can’t have.

  খ

  Unique can have single NULL value but Primary can’t have even single.

  গ

  Both can have duplicate values

  ঘ

  None of the Mentioned
• A _______________ key is a minimal super key
  ক

  Primary

  খ

  Foreign

  গ

  Candidate

  ঘ

  Non-Prime
• How can a SQL developer add a key on a table?
  ক

  While creating a table

  খ

  With Alter table command

  গ

  With SQL server Properties window

  ঘ

  All of the Mentioned
• Which of the following is not a restriction for a table to be a relation?
  ক

  The cells of the table must contain a single value

  খ

  All of the entries in any column must be of the same kind

  গ

  The columns must be ordered

  ঘ

  No two rows in a table may be identical
• When the values in one or more attributes being used as a foreign key must exist in another set of one or more attributes in another table, we have created a(n):
  ক

  Transitive Dependency

  খ

  Insertion Anomaly

  গ

  Referential Integrity Constraint

  ঘ

  Normal Form
• Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that:
  ক

  A -> B

  খ

  A -> C

  গ

  A -> (B,C)

  ঘ

  (B,C) -> A
• Anomalies are avoided by splitting the offending relation into multiple relations, is also known as
  ক

  Accupressure

  খ

  Decomposition

  গ

  Precomposition

  ঘ

  Both Decomposition and Precomposition
• In a given relationship R, if an attribute A uniquely defines all other attributes, then the attribute A is a key attribute which is also known as the _________ key.
  ক

  Candidate

  খ

  Join

  গ

  Functional

  ঘ

  None of the Mentioned
• A ___________ is an indirect functional dependency, one in which X->Z only by virtue of X->Y and Y->Z.
  ক

  Multivalued Dependencies

  খ

  Join Dependency

  গ

  Trivial Functional Dependency

  ঘ

  Transitive Dependencies
• Every constraint on the table is a logical consequence of the table’s
  ক

  Fourth normal form

  খ

  Fifth normal form

  গ

  Domain/key normal form

  ঘ

  None of the Mentioned
• A table is in 3NF if it is in 2NF and if it has no ____________
  ক

  Functional Dependencies

  খ

  Transitive Dependencies

  গ

  Trivial Functional Dependency

  ঘ

  Multivalued Dependencies
• The ___________ normalization introduced by Chris Date, Hugh Darwen, and Nikos Lorentzos.
  ক

  Third

  খ

  Fourth

  গ

  Fifth

  ঘ

  Sixth
• A table is in BCNF if it is in 3NF and if every determinant is a ___________ key.
  ক

  Dependent

  খ

  Normal

  গ

  Candidate

  ঘ

  Both Normal and Candidate
• Find the SQL statement below that is equal to the following: SELECT NAME FROM CUSTOMER WHERE STATE = ‘VA’;
  ক

  SELECT NAME IN CUSTOMER WHERE STATE IN (‘VA’);

  খ

  SELECT NAME IN CUSTOMER WHERE STATE = ‘VA’;

  গ

  SELECT NAME IN CUSTOMER WHERE STATE = ‘V’;

  ঘ

  SELECT NAME FROM CUSTOMER WHERE STATE IN (‘VA’);
• The benefits of a standard relational language include which of the following ?
  ক

  Reduced training costs

  খ

  Increased dependence on a single vendor

  গ

  Applications are not needed

  ঘ

  All of the Mentioned
• The wildcard in a WHERE clause is useful when?
  ক

  An exact match is necessary in a SELECT statement

  খ

  An exact match is not possible in a SELECT statement

  গ

  An exact match is necessary in a CREATE statement

  ঘ

  An exact match is not possible in a CREATE statement